Temporary soil release resins applied to fabrics by spraying

ABSTRACT

A laundering process and novel laundering composition used to impart temporary soil release properties to textile fabrics by impregnating the fabrics with an acrylic resin in the final step of a laundering operation, usually in the sour operation. The fabrics are then dried leaving a residue of the resin on the fabrics which helps remove after acquired stains. The resin impregnation can be combined with fabric finishing treatments such as blueing, sizing, brightening and softening. The process is repeated with each subsequent laundering of the fabrics to obtain optimum soil release and stain removal. The laundering compositions comprise water, acrylic resin, and laundry sour or other fabric finishing agent.

[451 Aug. 19,1975

1 1 TEMPORARY SOIL RELEASE RESINS APPLIED TO FABRICS BY SPRAYING [75]Inventor: Harry Creston Mandell, Jr., Wayne,

[73] Assignee: Pennwalt Corporation, Philadelphia,

[22] Filed: Oct. 17, 1973 [21] Appl. No.: 407,115

Related US. Application Data [62] Division of Ser. No. 171,362, Aug. 12,1971, Pat. No.

[52] US. Cl 427/155; 427/421 [51] Int. Cl. B44d 1/22 [58] Field ofSearch 1 17/66, 143 A, 104 R,

117/161 UC, 139.5 A, 161 UH, 161 UB. 117/161 UF, 138.8 F; 260/296 RW,29.6 H

$377,249 4/1968 Marco 8/1156 3,448,462 6/1969 Thomas 117/161 UB3,575,899 4/1971 Pryor et a1. 117/1 39.5 C

Primary ExaminerRalph I-Iusack Assistant ExaminerTheodore G. DavisAttorney. Agent, or Firm-Robert G. Danehower 5 7 ABSTRACT A launderingprocess and novel laundering composition used to impart temporary soilrelease properties to textile fabrics by impregnating the fabrics withan acrylic resin in the final step of a laundering operation, usually-inthe sour operation. The fabrics are then dried leaving a residue of theresin on the fabrics which helps remove after acquired stains. The resinimpregnationcan be combined with fabric finishing treatments suchasblueing, sizing, brightening and softening. The process is repeated witheach subsequent laundering of the fabrics to obtain optimum soil releaseand stain removal.

The laundering compositions comprise water, acrylic resin, and laundrysour or other fabric finishing agent.

4 Claims, No Drawings TEMPORARY SOIL RELEASE RESINS APPLIED TO FABRICSBY SPRAYING This is a division of application Ser. No. 171,362, filedAug. 12, 1971 now US. Pat. No. 3,782,898.

BRIEF SUMMARY OF THE INVENTION Deeply set grease and oil stains haveproved difficult to remove by laundering, especially in the syntheticfabrics made of polyester or mixtures of polyester and cotton. Inaccordance with this invention, I have discovered a method of treatingtextile fabrics with acrylic resins in the final stage of the launderingprocess which impregnates the fabrics with the resins to providetemporary soil release characteristics. The resin impregnation of thefabrics assists in the removal of deeply set stains and at the same timethe fabric acquires soil resistant properties so that any substantiallyacquired stain does not become deeply and permanently attached. Theimpregnated resin is largely removed in the next laundering of thefabric so that a new application of the resin must be made on eachsubsequent laundering to obtain and maintain optimum soil releasecapability.

The acrylic resins are added to the last stage of the laundering cyclewhich is usually the sour operation. Moreover, the resins could be addedto other fabric finishing treatments such as blueing, sizing,brightening or softening provided it is in the last operation. Theconcentration of the resin in the sour or other finishing solution willbe an amount so that the quantity of resin left on the fabric afterdrying will provide an effectual means for removing soil and stains.This is known as an effective amount of acrylic resin. Generally, theconcentration of the resin in the treating composition will be at leastonequarter part resin per 5,000 parts by weight of souring solution orother treating solution such as blueing, or sizing. A preferredconcentration range is one-half to 1 part of resin per 5,000 parts ofsour, or other treating solution while concentrationsas high as 3 partsof resin per 5,000 parts of treating solution have been used forreclamation of deeply soiled garments.

The acrylic resin is generally an aqueous solution although some resinsmay be in the form of aqueous emulsions. The pH of the resin treatingsolution must be within the range of 4 to 6.5, preferably within a rangeof 4.5 to 6.0. The temperature during the impregnation treatment is notcritical but is usually within the range of 70 to 180F. preferablywithin the range of 95 to 180F. These conditions of temperature and pHapply to either souring liquids or other fabric finishing treatmentsolutions in which the acrylic resin in suspended or is in solution.

The resin treating solutions are separated from the fabrics byconventional laundry practice leaving the fabrics wet and impregnatedwith resin. The fabrics are then dried by conventional laundry practiceleaving the resin on the fabrics. Drying temperatures of 70 to 350F aresatisfactory. The amount of resin left on the fabric after drying is inthe order of 0.005 to 0.05 percent by weight. A preferred amount ofresin is 0.01 to 0.02 percent by weight on a dry basis.

Thus, the retained resin acts as a parting layer or film forsubsequently acquired stains permitting their easy removal in subsequentlaundering operations. The removal of the resin itself in subsequentlaundering operations further increases the removal of soil and stains.Additionally, the impregnated resin attacks deeply seated stains andgreases already present so that repeated treatments with the resineventually restore a badly soiledfabric to a usable condition.Generally, about three launderings including a resin treatment in eachcycle are required to restore a fabric. The acrylic resins used in myprocess are mixtures of one or more homopolyme'rs" and copolymersobtained fromacrylic acid or methacrylic acid, and alkyl esters ofacrylic acid and methacrylic acid.

The resin treating process is thoroughly compatible with present daylaundering, and normal laundering conditions of temperature anddetergent concentration for washing and rinsing precede the resintreatment of the fabrics.

Also in accordance with my invention, I have discovered novel resincompositions for treating fabrics during laundering to give themtemporary soil release characteristics. These compositions comprise theacrylic resins discussed above in aqueous mixtures with laundry sours,and/or fabric finishing agents such as blues, brighteners, sizingagents and softeners.

In a laundry souring solution, sufficient souring chemical must bepresent to give a pH within the range of4 to 6.5 preferably within therange of 4.5 to 6.0. The same conditions of pH and acrylic resinconcentration apply to other fabric finishing compositions comprisingwater, resin and fabric finishing agent such as blueing, sizing,brightener, or softener.

In another aspect of my invention, the acrylic soil release resin may beapplied by spray to a textile fabric which has previously been dried.The spray propellant may be air, carbon dioxide, hydrocarbons orfluorocarbons. The fabrics are dried after spraying to remove the sprayliquid. The clothes may be dried on racks or by tumbling in anair-clothes dryer or by ironing. Drying temperatures may vary from roomtemperature to 350F. Example 8 is illustrative of this aspect of myinvention.

DETAILED DESCRIPTION OF THE INVENTION In recent years the use of fabricswhich are made from blends of different textile fabrics has becomeincreasingly common. One of the more popular of these mixtures ispolyester with cotton fiber in a ratio frequently containing from 50 topercent polyester. These fabrics are frequently treated to provideimproved strength to the cotton portion, to improve hand or quality oftexture, to provide permanent press characteristics and to provide soilrelease characteristics.

It has been commonly observed that polyester and other synthetic fiberswith or without permanent press or other resin finish are unusuallydifficult to clean in a conventional laundering operation. Moreparticularly, polyester cottons are especially susceptible to oilystains that become deeply set and are not easily removed. The polyesterfibers are relatively hydrophobic and the conventional water launderingsystems cannot penetrate the fabric to reach the stain and effect itsremoval.

Drycleaning is being used to remove these deeply set grease stains fromtreated or untreated mixed fiber blends, but drycleaning suffers fromthe disadvantage that it is relatively much more expensive thanlaundering and drycleaning does not readily remove the water solubleportion of the soil which is usually present in large quantities.

l l have conceived a process of treating textile fabrics in the laststep ina laundering process in such a way that greasy soil stains do notbecome deeply and permanently attached and are readily removed insubsequent laundering operations. The essence of my discovery is thetemporaryimpregnation of the fabrics with an acrylic resin. The acrylicresin provides a means for flushing away subsequently acquired stains inthe next laundering of the fabric. The resins are not permanentlyattached to the fabric and are generally nearly all removed in the nextlaundering. To the extent that the resins are not all removed in thenext laundering they remain to assist in the removal of after acquiredstainsf Most of the applied resin is removed in the next laundering ofthe fabric so that a new application of the resin must be made on eachsubsequent laundering to obtain and maintain optimum soil releasecapability.

In addition to the ability to resist and facilitate the removal ofsubsequently acquired stains, the resin treatment which I havediscovered assists in the removal of previously acquired deeply imbeddedstains. l have observed that after two or three resin treatments ashereinafter described, that deeply imbedded stains are effectivelyremoved. Many fabrics which have been soiled so badly and which couldnot be cleaned by conventional laundering have been restored to normalservice as a result of the application of successive treatments inaccordance with my invention. Generally about three cycles of my processare required to restore a badly soiled garment. An unexpected benefit ofmy treatment is that the textile fabric so treated has a distinctlyimproved hand, size and texture, rendering them easier to finish and.more aesthetically appealing.

The essence of my invention is the discovery that acrylic resins of thetypes hereinafter disclosed may be applied to textile fabrics as a partof a final stage of a laundering operation whereby there is achieved avery low level of resin impregnation in the fabric. The impregnation ofthe acrylic resins on the textile fabrics is on the order of 0.005 to0.05 percent by weight on a dry basis. A preferred amount is 0.01 to 0.2percent by weight. It was an unexpected discovery to learn that this lowlevel of resin impregnation would assist in the removal of deeplyimbedded stains and give a textile fabric the ability to resistsubsequently acquired stains. It was also unexpected to discover thatrepeated treatments of the fabrics with a low level of acrylic resinimpregnation would give fabrics a soil release capability and desirablefinishwhich, although only temporary, is equivalent in performance tothe much more expensive process whereby the soil release resins arepermanently attached to textiles by chemical means in the textilemanufacturing process.

RESINS The resins suitable for practicing this invention are all derivedfrom homopolymers and copolymers of .acrylic acid and methacrylic acid.

. provide satisfactory soilrelease resins for textile fabrics in myprocess. I

In addition to the homopolymers described above, various copolymersformed by copolymerizing acrylic including the acid homopolymers providesuitable soil release resins. The alkyl substituents are C 1 through Cgroups. Mixtures of these copolymers are also satisfactory temporarysoil release resins.

Esters suitable for copolymerizing with acrylic acid or methacrylic aacid to provide satisfactory temporary soil release resins are methylacrylate, ethyl acrylate,

n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, iosbutylacrylate, methyl methacrylate, ethyl methacrylate, n-propylmethacrylate, isopropyl'methacrylate,

n-butyl methacrylate and isobutyl methacrylate.

In addition to the copolymers described above which are useful temporarysoil release resins, mixtures of the homopolymers with the variouscopolymers described above are particularly useful as temporary soilrelease resins.

Any ratio of mixtures of the homopolymers or mixtures of homopolymersand copolymers described above provides suitable temporary soil releaseresins for practicing my invention.

A preferred temporary soil release system comprises mixtures of thehomopolymer of acrylic acid and copolymer formed from ethyl acrylate andmethacrylic acid,

The above homopolymers and copolymers and their mixtures described'above which provide satisfactory temporary soil release resins forfabrics in my new laundering process and compositions are hereinafterre-.

ferred to in the specification and claims as acrylic resins.

The resin homopolymers and copolymers are conveniently added to thelaundry machine in the form of water solutions, emulsions ordispersions. For example, polyacrylic acid is commercially available as25 percent by weight aqueous solution. The acrylic resins are usuallyadded directly to the souring solution in the laundry machine althoughthe resin could be added to any reserve supply of souring solution.

SOURING SOLUTION 'The souring solutions are acid solutions generallymade from one of the fluosilicates such as sodium fluosilicate. Theconcentration of the resin in thesouring solution is not critical.However, there must be present sufficient resin in the souring solutionso that when the garment is dried there will remain on the fabricsufficient soil release resin to provide a means for removing soil andstains. Such a concentration of resin in the souring solution is knownas an effective amount. Generally, the concentration of resin in thesouring solution will be at 1 part of resin by 'weight per 5,000 partsof souring solution. Good results have been obtained at one half partresin per 5,000 parts of souring solution, while some improvement insoil release properties has been obtained atone-fourth part of resin per5,000 parts of souring solution.

Higher resin concentrations are generally not needed for garmentsreceiving regular resin treatments. However, higher concentrations maybe used for reclamation treatment of severly soiled garments. In thisspecial The souring operation in a commercial laundry is generally thelast operation in the laundry process. For economic reasons. theapplication of the soil release resin is combined with the souringoperation in order to avoid a separate laundry operation. However, iffor some reason it is not desired to combine the sour and soil releaseimpregnation treatment, they can be performed separately provided theresin treatment isthe last operation in the laundry process. The'resinimpregnation must be the last operation to prevent loss of the resins byany subsequent laundering involving immersion in or rinsing of thefabrics with water which would wash away most of the resin.

The sour operation removes the alkalinity in the fabrics which is notremoved by the water rinses. Generally from two to five water rinses areemployed prior to souring. The first water rinse is usually at the washtemperature of 180 to 190F. Subsequent rinsesare at progressively lowertemperatures down to room temperature. Failure to remove nearly all ofthe alkali can cause skin irritation from the fabric.

The sour solutions are prepared from acid salts and other acidicmaterials. The silicofluorides are the most common sours. Thesilicofluorides are obtained in the form of ammonium. sodium, magnesiumor zinc fluosilicates. Other materials used in laundry sours are sodiumand ammonium acid fluoride, ammonium chloride and acetic acid. Liquidsources of sours are hydrofluoric acid and fluosilicic acid.

The souring operation is generally done within a pH range of 4 to 6.5and the amount of sour added will depend on the residual alkalinity fromthe washing cycle, the alkalinity of water being used and the desiredpH. Generally from 1 oz. to 12 ozs. of sour are used per 100 lbs. of drytextile fabrics. Generally from 350 to 500 pounds of water are used ineach laundry operation for each 100 pounds of dry fabrics.

The combined souring operation and application of the acrylic soilrelease resin to the fabrics is undertaken at a temperature within therange of 70 to 180F. Preferably, the temperature will be within therange of 95F and 180"Fv In combining the application of the sour andsoil release resin to the fabrics, means must be taken to secure uniformmixing and suspension of the resin. The normal rotation of the laundrywheel is satisfactory for this purpose.

One or more of the following fabric finishing chemicals may be combinedwith the souring and resin application to the fabrics: Blueing isgenerally applied to white goods at the rate of one thirty-second oz.per 100 pounds of white goods; Fabric brighteners are applied at therate of 1 oz. per 100 pounds of dry fabrics; Fabric softeners areapplied to the sour solutions at the rate of 1 to 2 ozs. per 100 poundsof dry fabrics.

Sizing is also compatible with the laundry souring solution and soilrelease resin. Sizing is generally wheat or corn starch and is used at aconcentration of from 8 oz. to llb. per 100 pounds of fabrics. Starch isapplied to nthe souring at the same concentration. The

above concentrations will provide an effective amount of fabricfinishing agent. It will be appreciated that the concentration of fabricfinishing agents in the souring solution are well known in the art,These concentrations will vary depending on local water conditions andthe effect desired by the individual laundry operation.

DRYING The souring operation combined with resin impregnation and/orother fabric finishing treatment takes place within about 3 to 10minutes, preferably within 5 to 8 minutes. Following the treatmentperiodin souring solution containing the acrylic resin the textilefabrics are separated from the treating solution and are then dried.Separation ofthe resin-sour solution is usually accomplished bycentrifugal extraction or by hydraulic pressing.

There is generally retained on the fabricafter separation of the souringsolution or other fabric finishing solution about an equal weight of thetreating solution. For every 100 pounds of dry clothes treated therewill be about 100 pounds of sour solution. When the resin concentrationin the sour is 1 part resin per 5,000 parts by weight of souringsolution, then 100 pounds of clothes will have retained one-fiftieth ofa pound of resin or 0.02 percent resin. When the resin concentration inthe souring solution is one-fourth part resin to 5,000 parts by weightof souring solution, the resin retention on the fabrics is about 0.005percent by weight. At one-half part resin per 5,000 parts by weight ofsouring solution, the resin impregnation on the fabrics after dryingwill be about 0.01 percent by weight. At 2 parts resin per 5,000 partsof souring solution the resin impregnation on the fabrics will be about0.05 percent by weight. A preferred impregnation on the dry fabrics isabout 0.01 to 0.02 percent by weight.

The wet resin impregnated fabrics are dried at temperatures varying fromroom temperature to about 350F. Drying is accomplished in conventionalair dryers for clothes or by ironing or by pressing. Ironingtemperatures are generally about 350F. Somewhat lower temperatures aregenerally used in the air dryers and satisfactory drying can beaccomplished with air temperatures as low as about F or roomtemperature. The water is more rapidly removed at higher temperaturesand temperatures of 150 to 350F are preferred.

The best mode of practicing my invention may be understood from aconsideration of the following examples:

EXAMPLE 1 In a Milnor Washer, Model No. 600-CWM-5 of 35 pounds dryclothes capacity was placed 24 pounds of cotton rags and 1 pound of 10inch square test swatches of white shirting, 65/35 polyester cottonfinished with a durable press resin. The washer was filled with water tothe 16 gal. level and 0.25 pounds of a commercial all-in-one laundrydetergent was added. The water tem' perature was 150F. After 10 minutesof agitation. the system was drained, refilled, and 0.125 pounds ofdetergent was added. it was agitated 5 minutes at l5()F. and thendrained. There were four 30 gal. water rinses, one each at 150F., 130F.,1 10F., and F. After the four rinses, water was added to the 16 gal.level at 1 15F, the pH adjusted to 4.5 by adding sodium'fluosilicatelaundry sour, and the system was agitated for 1 minute. At this timethere was added 1 pint of an aqueous resin solution containing 3.9percent by weight of a 25 percent by weight polyacrylic acid solutionand 9.0 percent by weight of a 20 percent by weight solution of acopolymer of ethyl acrylate and metharcylic acid in the ratio of 2.7mols metharcylic acid to 1 mol of ethyl acrylate. The one pint of resinsolution provides 4.4 grams of polyacrylic acid and 8.7 grams of thecopolymer. The system was agitated for 8 more minutes, drained, andcentrifugely extracted for 1 minute. The cotton rags and test swatcheswere then dried by ironing for seconds at 350F.

The test swatches were soiled by placing on them at two separate spots,5 drops of refined material oil and 5 drops of used motor oil. Thesespots were then blotted and allowed to age for a minimum of one halfhour. The staining and rating procedure was the standard method of theAmerican Association of Textile Chemists and Colorists, Test 130-1969.

Control swatches made from fabric identical to the test swatches werelaundered in exactly the same manner as the foregoing procedure with theexception that no polymer and copolymer mixture was added to the souringstep.

The control and the test swatches were then subjected to threeadditional cycles of laundering, treatment with polymer and copolymersolution, drying, and staining, the subsequent stains being placed atdifferent locations on the test swatches. The test series was carriedout with resin addition in each souring step, and the control series wascarried out with no resin addition at any time.

Following each ironing, the color intensity of the spots was evaluated.Rating of 5 represents complete disappearance of spot.

The results after 4 cycles are given in Table 1.

TABLE I stains. After four complete cycles the stains applied at the endof the first cycle were nearly completely gone in the case of the testfabrics treated with resin and were still distinctly visible in the caseof the untreated control fabric.

EXAMPLE 2 In a Milnor Washer, Model No. 600-CWM-5 of pounds capacity wasplaced 24 pounds of cotton rags and 1 pound of IO inch square swatchesof white shirting, /35 polyester cotton finished with a durable pressresin. The washer was filled with water to the appropriate level and0.25 pounds of a commercial allin-one laundry detergent was added. Thewater temperature was 150F. After 10 minutes of agitation, the systemwas drained, refilled, and 0. l 25 pounds of detergent was added. It wasagitated 5 minutes at 150F and then drained. There were four high levelrinses, one each at 150F, 130F, 1 10F, and 90F. The water was raised tothe low level (16 gal.) at 120F. Three pints of the aqueous resinsolution of Example 1 were added to the water. The resultant pH was 6.1.The system was agitated for 5 minutes, drained and centrifugelyextracted for 1 minute. The cotton rags and test swatches were then airdried at 73F for 2 /2 hours.

The test swatches were soiled by placing on them at two separate spots,5 drops of refined mineral oil and 5 drops of used motor oil. Thesespots were then blotted and allowed to age for a minimum of one halfhour.

, Control swatches were prepared in exactly the same manner except thatno resin mixture was added in the last step. The results after one wash,then application of soil release resin, then staining, then oneadditional wash showed control values of 3.5+ and 2.5 for mineral oiland motor oil respectively, and test value of 3.5+ and 3.0 for therespective stains on the resin treated fabric.

Spots Applied Spots Applied End of 2nd Cycle End of lst Cycle SpotsApplied End of 3rd Cvclc Mineral Motor Mineral Motor Mineral Motor OilOil Oil Oil Oil Oil Test Swatches 5.0 4.5 4.5+ 4.0 4.5 3.5+ Control 4.5+3.0 4.0+ 3.0 4.0+ 2.5

After the first laundering following treatment with resin and staining,the stains on the treated fabric were seen to be slightly lighter thanthe stains on the untreated fabric. That is, the laundering stagefollowing resin treatment was more effective in removing the TABLE llGrading at the (ompletion of Four Cycles of Spots Applied at the End oflst Cycle Then Subjected to Three Full Cycles of 'lreatment'l'cmperature ol Souring (S: Applica- F 85F )5F l l5F l40l lF tionSolution Min. Mot. Min. Mot. Min. Mot. Min. Mot. Min. Mot. Mm. Mot. OilOil Oil Oil Oil Oil Oil Oil Oil Oil Oil Oil 'l'csl $\\;llLhc.\ .0 3.0+4.54 3.0+ 4.) .0 4.5+ .0 4.0 5.0 4.0

('untrv R5 311 4 o 2.5+ .0 4.5+ 3.0+ 4. 3.0 4.54 3.0

It is seen that even at an application solution temperature as low as70F. there is a small effect of the polymer treatment. More pronouncedeffect is obtained at 95F. and higher.

EXAMPLE 4 The test and control experiments of Example 1 were carriedout, except that the damp test swatches, after centrifugal extraction,were tumbled in a hot air dryer at l50F. Following are the results after4 cycles of resin impregnation treatments with comparative controls.

TABLE III then tumble dried in a hot air drier at 200F. air temperature.

The test swatches were soiled by placing on them at two separate spots,drops of refined mineral oil and 5 drops of used motor oil. These spotswere then blotted and allowed to age for a minimum of one half hour.

Control swatches were prepared in exactly the same manner as theforegoing procedure with the exception that no polymer and copolymermixture was added to the souring step.

The controland the test swatches were then subjected to three additionalcycles of laundering, treat- Spots Applied End of 2nd Cycle SpotsApplied End of 3rd C vcle Mineral Motor Mineral Motor Mineral Motor OilOil Oil Oil Oil Oil Test Swatches 4.5+ 4.5+ 4.5+ 4.0+ 4.5 3.5+ Control4.5 2.5+ 4.0+ 2.5+ 4.0+ 2 s EXAMPLE 5 ment with polymer and copolymersolution, drying. and

In a Milnor Washer, Model No. 600-CWM-5 of 35 pounds capacity was placed24 pounds of cotton rags and l pound of l0 inch square swatches of whiteshirting, 65/35 polyester cotton finished with a durable press resin.The washer was tilled with water to the appropriate level and 0.25pounds of a commercial allstaining, the subsequent stains being place atdifferent locations on the test swatches. The test series was carriedout with polymer addition in each souring step, and the control serieswas carried out with no polymer addition at any time.

The results after 4 cycles of treatment are given in Table IV.

TABLE IV Spots Applied Spots Applied Spots Applied in-one laundrydetergent was added. The water temperature was 150F. After minutes ofagitation, the system was drained. refilled, and 0.l pounds of detergentwas added. lt was agitated 5 minutes at 150F and then drained. Therewere four high level rinses, one each at 150F, 130F. 1 10F, and 90F.Then water was The experiment of Example l was carried out in whichvarying amounts of sodium fluosilicate souring agent were used toachieve various pH of the system in which the soil release polymers wereapplied to the textile. The results are tabulated in Table V.

TABLE V Grading at the Completion of the Second Cycle of Spots Appliedat End of lst Cycle Then Subjected to One Full Cycle of Treatment pH ofApplication 7.9 7.4 6.9 6. l 5.8 4.5 Solution Min. Mot. Min. Mot. Min.Mot. Min. Mot. Min. Mot. Min. Mot. Oil ()il Oil Oil Oil Oil Oil Oil OilOil Oil Oil Test Swatches 3.5 2.0+ 3.5 2,5 3.5+ 2.5 3.5+ 3.0 4.0 3.0+ .53.5+ Control 3.5 2.0 35+ 2.5 3.5+ 2.5 3.5+ 2.5 3.5+ .5 4.0 2.5

raised to the low level 16 gal.) at l20F. The pH was adjusted to 4.] byaddition of ammonium fluosilicate sour and then 5 oz. of wheat starchwere added to the souring solution. After 1 minute of agitation, therewas added 1 pint of the resin solution described in Example 1. Thesystem was agitated 8 more minutes. then centri fugely extracted for 1minute. The textile fabrics were It is observed that improved soilremoval as compared to the control is obtained at a treating solution pHof about 6.5 to a pH of about 4. At a pH lower than 4, the solution willproduce fabric tendering and other undesirable side effects and is notnormally used in commercial laundering. A preferred pH range is observedbetween about 4.5 and 5.8.

EXAMPLE 7 The procedure of Example 1 was carried out with a variety oftextiles. These included 65/35 polyester cotton with crease resistantfinish, rayon. pure cotton, silk,

EXAMPLE 9 The procedure of Example 1 was carried out in which the ratioof the mixture of polymer solutions added to the souring solution wasvaried. The results of the exnylon, pure polyester (Dacron), wool andacrylic fabperlments are reported m Table VI. Percentages are by rics.In every case there was an improvement in soil reweight.

TABLE VI Grading at the Completion of Three Cycles of Spots Applied atEnd of lst Cycle. 'l'hen subjected to Two Full Cycles oflrcatmcntComposition 13.5% of a 6.5% ol :1 25% 3.9% of a 13.57: of a of Polymer25% solution solution of 25% solution copoly- Solution (one ofpolyacrylic poly-acrylic of polyacrylic mcr* solution pint per acid inwater acid in water acid in water in water lb. load) gethcr withtogether with 6.571 of a 9.6% of a 20% 20% copolycopol vmcr* somer*solution lution in water in water Min. Mot. Min. Mot. Minv Mot. Min.Mot. Oil Oil Oil Oil Oil Oil Oil Oil Control 2.5+ 4.0+ 2.5 4.0+ 3.0 4.01H- copolymer of elhylacqlatc and methacrylic acid in mole ratio of l to2.7.

moval versus the control except that motor oil stain removal on rayonwas improved only very slightly.

EXAMPLE 8 control is obtained at all ratios.

EXAMPLE 1 0 It is observed that improved stain removal versus the Theprocedure of Example 1 was carried out except that the amount of soilrelease polymer added to the souring solution was varied. Results arereported in Table Vll.

TABLE VI] Grading at the Completion of Four Cycles of Spots Applied atthe End of lst Cycle, Then Subjected to Three Full Cycles of TreatmentAmount of Polymer Apt/25 lbs. VzpL/ZS lbs. 1 pt./25 lbs. 2 pt./25 lbs.Solution Textile Textile 'lextile Textile Added Min. Mot. Min. Mot. Min.Mot. Min. Mot. Oil Oil Oil Oil Oil Oil Oil Oil Test Swatches 4.5+ 3.0+5.0 3.5+ 5.0 4.5+ 5.0 4.5+ Control 5.0 3.0 4.5+ 3.0 3.0+ 4.5+ 3.0+

by weight solution of a copolymer (27 mole percent ethyl acrylate, and73 mole percent methacrylic acid), was packaged with fluorocarbonpropellent in a pressure container. This mixture was sprayed onto cleandry crease-resistant, 65/35 polyester textile until the textile wasslightly clamp to the touch. The wet weight increase was approximately 3percent of the dry weight, equivalent to a polymer add-on of about 0.09percent of the dry textile. The textile swatch was a subsequently driedby ironing at 360F, stained with 5 drops of motor oil, aged for at leastone-half hour and then laundered in a home washing machine with aconventional home laundry detergent at l l0F. After removal from thewashing machine the damp swatches were dried, sprayed again with thepolymer solution. then redried at ambient temperature. After 4 cycles oftreatment. the swatches sprayed with polymer solution showed a motor oilstain rating of 35+ compared with 3.0+ for the control, and a mineraloil stain rating of 5.0 compared with 3.0+ for the control.

[t is seen that slight results are obtained when as little as one-fourthpint of polymer solution is added per 25 pound load. Good improvement isobtained at one-half pint per 25 pounds and optimum results are obtainedwith l or more pints per 25 pound load.

EXAMPLE 1 1 The experiment and procedure of Example 1 is repeated inwhich the ratio of ethyl acrylate to methacrylic acid in the copolymeris varied. In general, good results are obtained if the copolymercontains more than about 1 mole of methacrylic acid per mole of ethylacrylate since the copolymer will be water soluble or dispersible.Conversely, if the copolymer contains less than about 1 mole ofmethacrylic acid per mole of ethyl acrylate the copolymer will beessentially insoluble and will therefore be ineffective in the practiceof this invention. Compositions up to and including purepolyrnethacrylic acid will perform well.

EXAMPLE 1:

The experiment of Example I was carried out, except that cotton and65/35 unfinished polyester/cotton were used as fabrics, and acommercially available sizing containing starch was added at the rate of4 ounces per 25 pounds of textile to the souring solution together withthe polymer solution.

washer at the 6 inches level at 120F. Six ounces of sodiumsilicofluoride sour and 36 ounces of starch-based sizing agent wereadded and allowed to distribute through a 2 minute agitation. Then 6quarts of polymer solution containing 3.9 percent by weight of a 25percent by weight aqueous solution of poly-acrylic acid together with9.6 percent weight of a 20 percent weight copolymer of ethyl acrylateand methacrylic acid in the TABLE Vlll Spot Applied Spot Applied Endollst C ele End of lst A: 2nd C \cle Observed Observed End of 2nd CycleEnd of 3rd Cycle Mineral Motor Mineral Motor Oil Oil Oil Oil Spot No. ll l 2 2 ('otton (test) 4.5+ 3.0 5.0 4.5 4.0-l- 3.0+ Cotton (control) 40+3.0 45+ 4.5 3.0+ Unfinished pol cotton (test) 4.5 3.0+ 5.0 4.5 3.5+ 3.5+Unfinished pol cotton (control) -l.0-- 2.5 4.0+ 4.0 3.0 .5

Spot Applied End of 1st. 2nd 5: 3rd Cycles Observed End of 4th CycleMineral Motor ()il Oil Spot No. l 2 3 l 2 3 Cotton (test) 5.0 5.0 4.54.5+ 4.0 3.5 Cotton (control) 5.0 4.5+ 4.5+ 4.0 3.5+ 3.5 Unfinishedpol). cotton (test) 5.0 5.0 4.0+ 4.0 4.0 3.5 Unfinished poly. cotton(control) 4.5+ 4.5 4.0 3.0 2.5+ 2.5

EXAMPLE 13 mole ratio of l to 2.7 in water was added and the sys- Blueindustrial work uniforms from an automotive repair shop, both shirts andpants; were loaded into a stainless steel washer 42 inches in diameterby 84 inches long. This washer was loaded with 200 pounds of permanentpress finished 65/35 polyester content blend garments. Hot water wasadded to the washer to the level of 6 inches 170 gallons) at atemperature of 190F. The garments were agitated by rotation of thewasher for 6 minutes to remove loose grease and soil, and the water wasremoved from the washer.

For the next step, water was added to the washer to the same level at190F, and 6 pounds of alkaline allin-one laundry detergent was added.There was also added 3 pints of emulsifiable kerosene to improvedetergency. After minutes of agitation, the washer was emptied. Thewasher was filled again to the same level with water at the sametemperature, and the clothes were agitated without the addition ofsupplies and then subsequently drained. The washer was filled again tothe same level and temperature. Three pounds of the alkaline detergentand 1 /2 pints of emulsifiable kerosene was added and the system wasagitated for 15 minutes.

After draining this system there followed 5 rinse stages. In each ofthese stages, water was added to 12 inches level (262 gallons), thendumped after 2 minutes of agitation. The temperature in each of these 5rinses was lowered in uniform steps from the original l90F to a finalrinse at 120F.

For the final operation. water was drawn into the tem agitated for eightadditional minutes. The washer was then drained and the garmentsextracted in a hydraulic extractor. The garments were eventually tumbleddry in a hot air dryer at F.

For purposes of this test, garments from an automotive repair shop werewashed in the manner described and then returned to service on a 2 weekcycle basis. After six months, that is 12 washing treatments and usecycles, the garments were seen to have only a few light residual stains,and were considered top quality in terms of overall appearance.

Control experiments were simultaneously conducted with identicalgarments used in automotive repair which were subjected to exactly thesame laundering cycles with the exception that polymer solution was notadded to the souring solutions. At the end of 6 months of service thesegarments were generally dingy in appearance and contained numerous darkgrease stains. Approximately 20 percent of the garments were consideredaesthetically unacceptable and had to be scrapped.

EXAMPLE 14 The unacceptable heavily soiled garments left from thecontrol part of Example 13 were laundered in exactly the same manner asin Example 13 except that 12 quarts of polymer solution containing 3.9percent by weight of a 25 percent by weight aqueous solution ofpolyacrylic acid together with 9.6 percent weight of a 20 percent weightcopolymer of ethyl acrylate and methacrylic acid in the mole ratio of lto 2.7 in water were added in the souring solutions. After twosubsequent laundcrings and polymer treatment there was seen to be adistinctly measurable improvement in appearance. After 4 cycles oftreatment with polymer followed by laundering (without intervening use).most of these garments were so free of stains and generally improved inappearance that they were returned to regular service. There was stillfurther improvement in appearance upon as many as six cycles of polymertreat- EXAMPLE 16 The experiment of Example 1 was carried out exceptthat there was added to the souring solution 8 ozs. of a 2 percent byweight solution of a quaternary ammonium type fabric softener prior tothe addition of the acrylic resin to the souring solution. The softeneragent was 2-heptadecyl-1-methyl-l((2-stearoylamide) ethyl)-imadazoliniummethyl sulfate.

The comparative test and control swatches are shown in Table IX.

ment and laundering, but little further improvement with more cycles oftreatment than that.

EXAMPLE 15 The following copolymer compositions can be prepared bystandard aqueous polymerization technique:

These copolymers are useful as temporary soil release resins in thepractice of my invention.

l. The process of treating a textile fabric with an acrylic resin toobtain temporary soil release comprising spraying the fabric withacrylic resin in an aqueous medium containing from about A to about 3parts of acrylic resin per 5000 parts of water and thereafter drying thefabric to remove water without curing the resin.

2. The process of claim 1 in which the acrylic resin is selected fromone or more of the resins consisting of polyacrylic acid,polymethacrylic acid and copolymers of acrylic acid or methacrylic acidwith alkylesters of acrylic acid and methacrylic acid said alkyl groupsbeing limited from 1 to 4 carbon atoms.

3. The process of claim 2 in which the resin is carried in spray form bya propellent selected from the class consisting of air, carbon dioxide.hydrocarbons and fluorocarbons.

4. The process of claim 1 in which the aqueous acrylic resin alsocontains one or more fabric finishing chemicals.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,900,606 Dated August 19, 1975 Inventor(s) Harry Creston Mandell, Ir.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Table L. Column 12, before the line starting with "Control" should binserted the following;

Test Swatches 4. 0+ 3. O 4. 0+ 3. 0+ 4. 5+ 4, 0 4. O 3. 0+

Signed and Sealed this twenty-fifth of November 19 75 [SEAL] Attest:

RUTH c. msou c. MARSHALL DANN Arresting Officer Commissioner ofParenlsand Trademarks

1. THE PROCESS OF TREATING A TEXTILE FABRIC WITH AN ACRYLIC RESIN TOOBTAIN TEMPORARY SOIL RELEASE COMPRISING SPRAYING THE FABRIC WITHACRYLIC RESIN IN AN AQUEOUS MEDIUM CONTAINING FROM ABOUT 1/4 TO ABOUT 3PARTS OF ACRYLIC RESIN PER 5000 PARTS OF WATER AND THEREAFTER DRYING THEFABRIC TO REMOVE WATER WITHOUT CURING THE RESIN.
 2. The process of claim1 in which the acrylic resin is selected from one or more of the resinsconsisting of polyacrylic acid, polymethacrylic acid and copolymers ofacrylic acid or methacrylic acid with alkylesters of acrylic acid andmethacrylic acid said alkyl groups being limited from 1 to 4 carbonatoms.
 3. The process of claim 2 in which the resin is carried in sprayform by a propellent selected from the class consisting of air, carbondioxide, hydrocarbons and fluorocarbons.
 4. The procEss of claim 1 inwhich the aqueous acrylic resin also contains one or more fabricfinishing chemicals.